&lt;title&gt;Compact short-pulse laser for near-field range-gated imaging&lt;/title&gt;

Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)

Loubriel²,

Már³

et al.

High gain photoconductive semiconductor switches (PCSS) are being used to produce high power electromagnetic pulses foc(1) compact, repetitive accelerators, (2) ultra-wide band impulse sources, (3) precision gas switch triggers, (4) optically-activated firesets, and (5) high power optical pulse generation and control. High power, sub-nanosecond optical pulses are used for active optical sensors such as compact optical radars and range-gatedhallistic imaging systems. Following a brief introduction to high gain PCSS and its general applications, this paper will focus on PCSS for optical pulse generation and control.PCSS technology can be employed in three distinct approaches to optical pulse generation and control: (1) short pulse carrier injection to induce gain-switching in semiconductor lasers, (2) electro-optical Q-switching, and (3) optically activated Q-switching. The most significant PCSS issues for these applications are switgh rise time, jitter, and longevity. This paper will describe both the requirements of these applications and the most recent results from PCSS technology.Experiments to understand and expand the limitations of high gain PCSS will also be described.

Section: General Applicationsmentioning

confidence: 99%

“…Some of the optical pulse testing and applications have also been described previously [4,5]. S-witching issues for short optical pulse 'generation control and experiments to improve PCSS for application will be summarized.…”

Section: Introductionmentioning

confidence: 99%

Photoconductive, semiconductor switch technology for short pulse electromagnetics and lasers

Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358)

Loubriel²,

Már³

et al.

High gain GaAs photoconductive semiconductor switches: switch longevity

Loubriel

Conference Record of the Twenty-Third International Power Modulator Symposium (Cat. No. 98CH36133)

Már

et al.

Optically activated, high gain GaAs switches are being tested for many different pulsed power applications that require long lifetime (longevity). The switches have p and n contact metallization (with intentional or unintentional dopants) configured in such a way as to produce p-i-n or ni-n switches. The longevity of the switches is determined by circuit parameters and by the ability of the contacts to resist erosion. This paper will describe how the switches performed in test-beds designed to measure switch longevity. The best longevity was achieved with switches made with diffused contacts, achieving over 50 million pulses at 10 A and over 2 million pulses at 80 A.

Properties of high gain GaAs switches for pulsed power applications

Digest of Technical Papers. 11th IEEE International Pulsed Power Conference (Cat. No.97CH36127)

Loubriel²,

Hjalmarson³

et al.

High gain GaAs photoconductive semiconductor switches (PCSS) are being used in a variety of electrical and optical short pulse applications. The highest power application, which we are developing, is a compact, repetitive, short pulse linear induction accelerator. The array of PCSS, which drive the accelerator, will switch 75 kA and 250 kV in 30 ns long pulses at 50 Hz. The accelerator will produce a 700 kV, 7kA electron beam for industrial and military applications. In the low power regime, these switches are being used to switch 400 A and 5 kV to drive laser diode arrays which produce 100 ps optical pulses. These short optical pulses are for military and commercial applications in optical and electrical range sensing, 3D laser radar, and high speed imaging. Both types of these applications demand a better understanding of the switch properties to increase switch lifetime, reduce jitter, optimize optical triggering, and improve overall switch performance. These applications and experiments on the fundamental behavior of high gain GaAs switches will be discussed. Open shutter, infra-red images and time-resolved Schlieren images of the current filaments, which form during high gain switching, will be presented. Results from optical triggering experiments to produce multiple, diffuse filaments for high current repetitive switching will be described.